Whenever this evidence is presented to people, you’ll usually get one of many different questions.

A commercial plane carries two different black boxes. Each black box carries one of two different recorders, a cockpit voice recorder and a flight data recorder.

The cockpit voice recorder records sounds from inside the cockpit, engine noise, stall warnings, and other sounds of interest.

Communications between Air Traffic Control, weather briefings and conversations between pilots and crew are also recorded.

The flight data recorder records at least twenty eight different parameters such as time, altitude, speed and heading.

Some also record more than 300 other in-flight characteristics, anything from auto-pilot mode to smoke alarms.

The recorders themselves are made from the most impervious metals known to man, and the information is recorded along with date and time, and spooled into a roll.

Any damage that is done to the roll is done to the outside, as opposed to the inside where the data is.

The 9-11 Commission says "The CVRs and FDRs from American 11 and United 175 were not found...”

Yet, the FBI claims to have found the passport of Satam al-Suqami, which managed to fly out of his pocket, through the explosion and onto the streets of Manhattan below.

So four different black boxes, made from the most resilient materials known to man, were destroyed.

Yet, a passport, made from a fragile material known as paper, managed to survive?

Ted Lopatkiewicz, spokesman for the National Transportation Safety Board, told CBS News that "It's extremely rare that we don't get the recorders back. I can't recall another domestic case in which we did not recover the recorders."

Turns out Ted’s right.

Nicholas DeMasi, a firefighter who helped the recovery efforts claims in the book Behind-the-Scenes: Ground Zero, “At one point I was assigned to take Federal Agents around the site to search for the black boxes from the planes. There were a total of four black boxes. We found three."

I guess it all comes down to who you’d rather believe.

FBI Director Robert Mueller said Flight 77's data recorder provided altitude, speed, headings and other information, but the voice recorder contained nothing useful.

As for Flight 93, it was the only flight where the cockpit voice recorded was recovered.

It was played for the families in April, 2002, but not before signing an agreement that they wouldn’t talk about it. They couldn’t even take notes.

And for some reason, the last three minutes of the tape were unaccounted for. The FBI had no explanation for the discrepancy.

Why would the 9-11 Commission tell us Flight 11 and 175’s recorders weren’t found?

Why would Robert Mueller tell us there’s nothing interesting on Flight 77’s?

What’s on the last three minutes of Flight 93’s CVR?

These are vital questions that need to be answered.

It’s an interesting postscript that Flight 93 was spotted on April 10th, 2003 at Chicago’s O’Hare Airport, by David Friedman, a United Airlines employee who records his flights.

The tail number, N591UA was spotted on United Airlines Flight 1111, a 757.

And according the FAA, both N591UA and N612UA, Flights 93 and 175, are still valid. But Flights 11 and 77 are listed as destroyed.

(note: On September 28th, 2005, the Tail Numbers were finally updated. Why did it take them 4 years?)

Not to mention that they were not even scheduled to fly on September 11th.

Flight Attendant Betty Ong allegedly placed a call from Flight 11.

According to the 9-11 Commission, although the conversation lasted 23 minutes, only 4 and a half minutes was recorded.

Does Ms. Ong sound like a woman on a hijacked plane who just saw three people murdered?

Why is nobody in the background screaming?

Flight attendant Madeline Sweeney allegedly talked with her ground manager Michael Woodward for 25 minutes.

She describes 4 hijackers. The FBI says there were 5.

She says the hijackers were in rows 9 and 10. The FAA says there were all in row 8.

Near the end, she screams, “I see buildings. Water. Oh my god!”

Madeline was a flight attendant out of Boston for 12 years. I think she would have recognized Manhattan.

A man claiming to be Mark Bingham called his mother, Alice, who was visiting his sister-in-law. The caller says, "Mom? This is Mark Bingham."

When was the last time you called your mother and used your full name?

The caller continues, ‘I just want to tell you that I love you. I’m on a flight from Newark to San Francisco and there are three guys on board and they have taken over the plane and they say they have a bomb.

I’m calling you from the Airfone,’ and then ‘You believe me, don’t you, Mom?’

‘Yes Mark, I believe you, who are these guys?’ Then he was interrupted by someone who was speaking in a low-toned male voice speaking what sounded like English.

After 30 seconds of muffled sounds, the caller repeats ‘I’m calling you with an Airfone.”

His mother asks him again, ‘Who are these guys?’

After another pause he returns and asks again, ‘You believe me, don’t you, Mom?’

There was another pause, and the phone just trailed off.

To date, none of these calls, except Betty Ong’s call to American Airlines, have been released to the public.

But to be honest, none of that matters.

Why? Because none of those calls could have possibly taken place.

Kee Dewdney of Physics911.net conducted some research of his own. In an experiment called Project Achilles, he took a series of cell phones onto a Cessna 172 and flew up to 8,000 feet.

At 4,000 feet he had a .4 success rate.

At 8,000 feet he had a .1 success rate.

For 32,000 feet, cruising altitude for a commercial airliner, he calculated a .006 success rate, less than one in a hundredth of a chance.

Don’t believe me? Even American Airlines has put their foot in the government’s mouth.

On July 15th, 2004, passengers aboard a commercial American Airlines flight were able to send and receive calls from their cell phones as if they were on the ground, thanks to a cell station that was installed into the plane.

"It worked great, I called the office. I called my wife. I called a friend in Paris. They all heard me great, and I could hear them loud and clear."

Why would American Airlines spend thousands of dollars on this technology in 2004 when cell phones worked so well on September 11th, 2001?

The cell phone calls were fake. No question about it.

So how is it possible to fake a person’s voice?

In 1999, the Los Alamos Laboratory in New Mexico revealed their voice morphing technology.

General Carl W. Stiener, the former Commander-in-chief of U.S. Special Ops declared on tape, “Gentlemen! We have called you together to inform you that we are going to overthrow the United States government."

Another example was Colin Powell saying, “I am being treated well by my captors.”

With just a 10-minute recording of somebody’s voice, they are able, in almost real time, to clone speech.

Steiner was so impressed, he asked for a copy.

So what about the hijackers?

On September 14th, 2001, the Department of Justice released the names of the alleged 19 hijackers.

But on September 23rd, the BBC reported that Waleed Al Shehri was alive and well in Casablanca, Morroco.

They also tracked down Abdulaziz Alomari, who is an engineer with Saudi Telecoms, and lost his passport while studying in Denver.

In the same article, FBI Director Robert Mueller admitted that “the identity of several of the hijackers is in doubt.”

So how many hijackers turned up alive? At least 9 of them.

Wail M. Alshehri is alive and well.

Mohand Alshehri is alive in Saudi Arabia.

Khalid Almihdhar is a computer programmer in Mecca.

Salem Alhazmi works at a chemical plant in Yanbu, Saudi Arabia.

Saeed Alghamdi is training to be a pilot in Tunis.

Ahmed Alnami is an administrative supervisor for Saudi Airlines.

We already covered Waleed and Abdulaziz.

And last but not least, Mohammed Atta's father claimed to receive a phone call from his son on September 12th.

On September 20th and 27th, Mueller admitted on CNN that there is "no legal proof to prove the identities of the hijackers."

...and the opening paragraph makes no mention of their absence.

Oh, that’s right. The bin laden confession tape.

Except there's a number of things wrong with this tape.

One, the tape itself is of very poor quality.

And two, the man in the video looks and acts nothing like bin Laden.

Not to mention he's wearing a gold ring...

...which is forbidden by Islamic law, and is never mentioned in the FBI’s description of him.

Compare this video to four other pictures of bin Laden. Does anybody else see a problem here?

Until the government can prove without a shadow of a doubt that al-Qeida was behind 9/11, the American people have every reason to believe otherwise.